The story behind the winning images: first in a series featuring winners of the PSM Photo Contest
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EmailThese images can be seen in the PSM conference room PSSB 271
PHOTO CAPTION: A microscope-guided process known as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to generate these images of Cladonia rangiferina, which demonstrate this lichen species’ capacity to take up copper and other metals from the mine tailings. Such uptake is potentially due to physiological adaptations that enable lichens to tolerate extreme edaphic conditions. This laser ablation work was conducted in collaboration with Michigan State University’s QBEAM core facility, founded by Dr. Thomas V. O’Halloran. “The contrast in copper uptake between lichens collected in contaminated versus reference sites is striking,” Friedman notes.
Investigating Plant-Microbe Interactions in Copper-Contaminated Stamp Sands
Discovering Clues in Copper-Contaminated Sands: PhD Student Explores Root Microbiomes in Harsh Environments
PhD Candidate Marc Friedman (Bonito Lab) Explores Root Microbiomes and Environmental Tolerance Mechanisms
Historic copper mining activities in Michigan’s Upper Peninsula have left behind extensive deposits of stamp sands—fine, metal-rich industrial waste material resulting from the mechanical separation of copper from host rock. These deposits present significant ecological challenges due to elevated concentrations of heavy metals, particularly copper, which are toxic to most plant and microbial life.
Marc Friedman, a PhD student in the Bonito Lab, is investigating how certain species—most notably Betula papyrifera (paper birch) and reindeer lichens—persist in or near these contaminated environments. His research integrates field sampling, metal content analysis, and root microbiome profiling to uncover mechanisms of tolerance or resilience.
Friedman’s current experimental framework involves cultivating B. papyrifera seedlings in controlled greenhouse conditions, using sterile growth media mixed to varying concentrations with stamp sands. A subset of these seedlings is inoculated with rhizosphere soil collected from field sites, allowing for comparison of microbial community structure and function under metal stress.
The primary objective is to characterize the root-associated fungal and bacterial communities, with a focus on determining whether any of the microbial taxa associated with birch roots affect metal uptake into the birch trees.
“Root tip microbiome analysis will be key,” Friedman says. “We expect to observe significant differences in microbial diversity and composition between stamp sand inoculated and uninoculated treatments.”
One unexpected speed bump in this process, Marc notes, is the difficulty in working with live woody plants. “They takes a long time to grow, there are so many variables, and seedling success rate is surprisingly low!”
To support microbial community profiling, Friedman is using a newly acquired instrument in the Genomics Core known as ‘the AVITI. “I’m super excited about learning both this new technology and for identifying taxa that may facilitate plant survival under metal toxicity.”
Broader Impacts
Friedman’s work contributes to a growing body of literature on plant-microbe-soil interactions in post-industrial landscapes, with implications for bioremediation, restoration ecology, and understanding of extremophile ecosystems. “Ultimately, we hope to identify microbial partners that enable revegetation of metal-contaminated sites, potentially restoring some level of ecological function and biodiversity.” Marc is supported by an NSF Graduate Research Fellowship and this research is supported through an NSF Understanding Rules of Life grant to PI Bonito.
